The EFA-21 doubles as a Power Module and RS485-USB Adapter that allows you to provide power and connect
an EFM-100 Atmospheric Electric Field Mill directly to your computer's USB port using a single device.

The Boltek BGW312 Ethernet Serial Server allows an EFM-100 and/or LD-250 to be remotely located any distance from the display computer using Ethernet to relay the data. Adding a long-range Wi-Fi Ethernet bridge also makes wireless operation possible up to several miles.